Microstructure and phase composition of cold Isostatically pressed and pressureless sintered silicon nitride

Abstract

The microstructure and physical properties of new Y₂O₃ and Al₂O₃ oxide-doped silicon nitride ceramics fabricated by cold isostatic pressing and free sintering were investigated. The phase composition of produced material was also studied by X-ray diffraction at room and elevated temperature. The fabricated ceramics featured a microstructure of Si₅AlON₇ grains with a fine-grained α-Si₃N₄ with a small amount of Y₂SiAlON₅. Described ceramics is attractive for many high-temperature structural applications due to beneficial combination of fine-grained structure with improved mechanical properties and small weight loss